Department of Electrical and Computer Engineering, University of British Columbia, Vancouver, BC, Canada.
IEEE Trans Ultrason Ferroelectr Freq Control. 2010 Nov;57(11):2421-36. doi: 10.1109/TUFFC.2010.1709.
This paper describes a new ultrasound-based system for high-frame-rate measurement of periodic motion in 2-D for tissue elasticity imaging. Similarly to conventional 2-D flow vector imaging, the system acquires the RF signals from the region of interest at multiple steering angles. A custom sector subdivision technique is used to increase the temporal resolution while keeping the total acquisition time within the range suitable for real-time applications. Within each sector, 1-D motion is estimated along the beam direction. The intra- and inter-sector delays are compensated using our recently introduced delay compensation algorithm. In-plane 2-D motion vectors are then reconstructed from these delay-compensated 1-D motions. We show that Young's modulus images can be reconstructed from these 2-D motion vectors using local inversion algorithms. The performance of the system is validated quantitatively using a commercial flow phantom and a commercial elasticity phantom. At the frame rate of 1667 Hz, the estimated flow velocities with the system are in agreement with the velocity measured with a pulsed-wave Doppler imaging mode of a commercial ultrasound machine with manual angle correction. At the frame rate of 1250 Hz, phantom Young's moduli of 29, 6, and 54 kPa for the background, the soft inclusion, and the hard inclusion, are estimated to be 30, 11, and 53 kPa, respectively.
本文描述了一种新的基于超声的系统，用于二维周期性运动的高帧率测量，用于组织弹性成像。与传统的二维流矢量成像类似，该系统从多个转向角度获取感兴趣区域的射频信号。采用定制的扇区细分技术，在保持总采集时间适合实时应用的范围内，提高时间分辨率。在每个扇区内，沿波束方向估计一维运动。使用我们最近引入的延迟补偿算法补偿内扇区和外扇区延迟。然后，从这些延迟补偿的一维运动中重建平面内二维运动矢量。我们表明，可以使用局部反演算法从这些二维运动矢量重建杨氏模量图像。使用商业流量体模和商业弹性体模对系统的性能进行了定量验证。在 1667 Hz 的帧率下，系统估计的流速与商用超声机的脉冲波多普勒成像模式手动角度校正测量的流速一致。在 1250 Hz 的帧率下，背景、软夹杂物和硬夹杂物的体模杨氏模量分别估计为 30、11 和 53 kPa。
